This method no longer attempts to retrieve region metadata from
CloudFront, as that file is no longer being maintained and the version
bundled with the SDK is likely to be more up-to-date.

It's deprecated to signal that it no longer has any possibility of
retrieving a newer set of metadata than was previously loaded. If you
are simply wanting to reinitialize from the bundled region metadata,
call initialize. If you want to maintain your own remote
copy of the region metadata and periodically refresh it at runtime,
call initializeFromURI.